Labor Day means two things: no work on Monday and WRFG-FM'S LABOR DAY BLUES FESTIVAL. The 21st edition, which takes place SEPT. 4, honors Duluth blues woman Sweet Betty Echols. Aficionados consider Sweet Betty, a belter born and raised in Duluth, to be the city's finest blues singer, thanks to her barnstorming performances throughout the States and Europe and revelatory appearances at local hot spots like Blind Willie's. Other performers set to take the stage include Sean Costello (right), Bluephonic, Delta Moon, Eden Brent, the Shadows and the Radio Ramblers. $12-$15. Noon-9 p.m. Park Tavern, 500 10th St. 404-523-3471. www.wrfg.org.